Glee star Cory Monteith, who plays Finn on the hit FOX musical, has checked himself into rehab.

Monteith's rep told People that he "has voluntarily admitted himself to a treatment facility for substance addiction. He graciously asks for your respect and privacy as he takes the necessary steps towards recovery."

This news obviously comes as a shock to all Glee fans, but in the past the actor has openly shared the struggles he's gone through with substance abuse. He said in an interview at the time that "I don't want kids to think it's okay to drop out of school and get high, and they'll be famous actors, too. ... But for those people who might give up: Get real about what you want and go after it." His family and friends previously admitted him to a rehab facility 11 years ago when he was 19.

Monteith's girlfriend, fellow Glee co-star Lea Michele, said in a statement, "I love and support Cory and will stand by him through this. I am grateful and proud he made this decision."

Glee's production company, 20th Century Fox TV, has also released a statement showing its support: "Cory is a beloved member of the Glee family and we fully support his decision to seek treatment. Everyone at the show wishes him well and looks forward to his return."

Glee still has two more episodes to film for season 4, which are set to air on May 2 and May 9. According to Deadline, filming is expected to continue as planned and Finn's absence will be explained on the show.